Step 5: The Sides

Step 6: Finishing

Paint and varnish the sides, and you're finished! Also add some traingles, arrows, or something else on the sides to show where the password should be...

In this Instructable I'll show how I made my cryptex.

There is already an Instructable on making a cryptex published lately, but I wasn't satisfied by that one. That cryptex was held together on the outside, like this. I prefer my cryptex held together from the inside, like this. That is by the way the 'real' cryptex, like it is used in the film. Those are harder to make.

INFORMATION ABOUT CRYPTEXES
A cryptex is a kind of lock with a password, that holds a roll of paper. Author Dan Brown said in his "Da Vinci Code", a book from some years ago, that Leonardo da Vinci invented it, to let messengers carry secret papyrus rolls that the messengers themselves may not read; only the sender and the recipient know the password. If the messenger would smash the cryptex to read the message, a vial containing vinegar which was rolled inside of the papyrus roll would also break even earlier than the cryptex itself, the vinegar would spread over the message, disolve the ink, making it unreadable.
The term 'cryptex' is actually made up by Dan Brown. I don't even know for sure that it's true that Da Vinci invented it, he never actually made one, he would have made a blueprint in his diary, but I never found that page of his diary(so I made my own blueprint, see the next step). What I do know, is that the vinegar thing doesn't work. It doesn't disolve the ink so much that it gets unreadable, it becomes only a little more vague. I tested it with Black Indian ink, several kinds of pen inks, marker pens, ecoline, pencils, and some more; it never worked, just like Wikipedia says.
In the Da Vinci Code, the cryptexes were used different than how they were meant by Da Vinci, in the story they use it as a part of a big puzzle, the answer to a riddle is the password of a cryptex, which contains another riddle that leads to another cryptex, etc. To my opinion the use of cryptexes in such a way is a bit ridiculous, the characters in the book could've just put the cryptex in the freezer so that the vinegar gets frozen, then they could saw it open without danger. But they didn't think of that easy solution in the book.

edit:
In the comments below, 'cavingboy92' came up with this genious way to make use of the vinegar vial: on the paper around the vial, don't write with ink, but also with vinegar. If you want to read the message, pour a PH indicator on it(like red cabbage juice), and you can see the text. Or you can just hold it under a low heat source like a light bulb, then you can see it too, because the acid will oxidate.
If the vial breaks, the piece of paper gets all drenched in vinegar, so it's absolutely sure that it's unreadable!Here is the proof that it works, tested by cavingboy92.
You could also just put the same inkin the vial as the ink where you wrote with on the paper, that would also destroy the message.
If you want more ways on how you could use a vial-break-delfdestroy mechanism, read throught the comments below, there are a lot of people giving suggestions for it, and also on improving the cryptex.
Finally, if you disolve a lot of salt in the vinegar, I think you can lower the freezing point of it so much that it can't get frozen in a normal kitchen freezer, then the freeze method also won't work so easily, you would have to find a special freezer in a lab or something.

Yes the original cryptex had papyrus . Which was paper of long ago and the vinegar would dissolve the paper . Paper used to be held together . It was tree pulp held together so the vinegar would break the bond . New paper is different but papyrus was a different paper. You can try making your own paper and using a solvent that would be undone by vinegar

OMG! This is totally awesome! Oh, why did Instructables digest came so late?! This cryptex idea would fit my puzzle-present for my friend's birthday tomorrow :( guess i'll make it anyway and present him the whole puzzle a bit later :/ I still wonder where to find tubes.. though, i guess i'll try in local store for such things.. Thanks for instructable :)

Thanks. I was just lucky, three of the tubes were in my dad's shed, and one tube came from an old damaged tent. But if you are going to make it just for a puzzle, I assume your friend keeps sportive and won't try to lock-pick or break your cryptex or something, you could also make it from cradboard tubes that go around posters. Or just paper... I could think of those tubes made from paper, with 10 or more layers of paper in thickness. It wouldn't hold against a thief, but for a puzzle present it would be good!

Better late than never ;) Three (or four?) years ago i finally made it from composite water pipes (PVC+Al+PVC ones) and it turned out really great. In case anyone looks for a material that is easy to handle and work with - PVC tubes are great for cryptex!

Well, i looked around for other instructables about Cryptexes, but they don't look that cool. I doubt i'll follow your idea to the letter, but i guess most of your instructable would be done. I guess i wouldn't work that hard on side caps. Maybe some strong glue, but no nails, i guess.

Hey, I had a question about doing this without a soldering iron, you say in the instructions you can use an oven what do you mean by "putting something under both sides" specifically. Can you clarify this a bit?

Another way you could make the vinegar vial work is is you wrote on something like tissue paper so the vinegar would dissolve it completely. I also like the idea of adding salt to prevent the freeze method. I was wondering if somebody could figure out a way to make a timed cryptex so that if it wasn't opened in time, the message would be destroyed. That would take some work, but would eventually be worth it for secret spy stuff.

thats actually exactly the point, had merijvnw read a little deeper into Dan Browns book, paper is not the material the note is written on but rather papyrus, which dissolves in vinegar, im not sure if someone else has already commented on this, but if so i just wanted to bring it to greater attention

Old post, I know.. I would look in to something electronic. Small timer (chip might work best), maybe a motor to crack the vial? Not sure how small it could be though. Sounds like a weekend project for me =)

In the book, pulling to hard on the ends of the cryptex actually moves a lever that has a point attached to it that presses down on the vinegar vile. When enough force is used (less force than required to break the cryptex) it cracks the glass vial containing the vinegar. this acion releases the vinegar which dissolves the papyrus.

I have given this thought with several designs, the best way to describe it is to make the lettered part have a piece under neath it that is an internal gear (http://www.rushgears.com/images/internalIMG.gif), with this you can adjust where the keys letters are on each letter ring. While I cannot describe this in great detail I suggest looking up how to change the code of your cryptex (the small ones Google distributed as part of their give away), the descriptions will show you all the internal workings and give the information you need.

You mention engraving on the PVC with a heated paperclip and that the fumes are harmless. It appears that the vapors from heating PVC can cause some forms of cancer (what doesn't these days though!) so it might be a good idea to do that in a well ventilated area.